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United States Patent |
5,297,947
|
Cardinali
|
March 29, 1994
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Rotary die moulding insert system
Abstract
A rotary die moulding machine used in the commercial production of baked
goods, which includes plastic inserts for the moulding cavities on the die
roll, is disclosed. Each moulding cavity is formed as a bore with a first
wall section extending inwardly from the outer surface of the die roll a
depth corresponding to the desired thickness of the baked good being
moulded, and a second wall section with an undercut edge beneath the first
wall section. The plastic insert has a face portion with a designed face
for imprinting a design into the dough, and has a base portion with a
protruding edge which conforms to the undercut edge of the second wall
section. The plastic insert fits snugly by snap action into the moulding
cavity. The plastic insert further provides improved release of bakery
dough. The plastic insert and the moulding cavity may be modified to
accommodate different shapes, thicknesses and designs of commercially
produced cookies, biscuits and other baked goods.
Inventors:
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Cardinali; Joseph (Millington, NJ)
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Assignee:
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Tiefenthaler Machinery Co., Inc. (Brookfield, WI)
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Appl. No.:
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878558 |
Filed:
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May 5, 1992 |
Current U.S. Class: |
425/194; 425/335; 425/362; 425/363 |
Intern'l Class: |
B29C 043/06 |
Field of Search: |
264/175
425/182,194,241,328,335,362,363,DIG. 235
|
References Cited
U.S. Patent Documents
1357141 | Oct., 1920 | Bibb | 425/194.
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2081724 | May., 1937 | Abbott | 425/194.
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2233688 | Mar., 1941 | Weidenmiller | 425/194.
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3205837 | Sep., 1965 | Fay | 425/362.
|
3302592 | Feb., 1967 | Werner | 425/362.
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4261692 | Apr., 1981 | Kuby | 425/194.
|
Foreign Patent Documents |
563683 | Dec., 1923 | FR | 425/362.
|
Other References
Biscuit and Cracker Handbook, Chapter 12, "Rotary Machine Cookies", pp.
97-103.
Weidenmiller Company, Rotary Molders, two-page brochure, 1986.
Weidenmiller Company, Rotary Molders, four-page brochure.
|
Primary Examiner: Bushey; Charles S.
Attorney, Agent or Firm: Nilles & Nilles
Claims
I claim as my invention:
1. A rotary die moulding machine for moulding bakery dough for baked goods
comprising:
a die roll having a curved outer surface with a plurality of moulding
cavities therein;
each moulding cavity having a first wall section with a shape and depth
corresponding to a shape and thickness of the baked goods to be moulded,
respectively, and having a second wall section with an under cut edge
beneath the first wall section, and having a flat bottom surface, whereby
the first wall section meets the undercut edge at first and second
peripheral areas of the cavity, and in a middle area of the cavity an
intermediate wall section extends from the first wall section inwardly to
the undercut edge of the second wall section;
plastic inserts snugly insertable into the moulding cavities for imprinting
designs into the bakery dough with each insert comprising:
a face portion having a shape corresponding to the shape of the first wall
section of the moulding cavity;
a base portion having a shape corresponding to the shape of the undercut
edge of the second wall section of the moulding cavity, and the base
portion having a flat base surface complementary to the flat bottom
surface of the mounding cavity; and
a designed surface on the face portion of the insert with a design to be
imprinted into the baked goods and the designed surface being
concentrically curved relative to the outer surface of the die roll
thereby forming a space for moulding the bakery dough to a uniform
thickness.
2. The rotary die moulding machine according to claim 1,
wherein the first wall section is machined at an angle of about fifteen
degrees (15.degree.) from the perpendicular of the outer surface of the
die roll at each point around the perimeter of the moulding cavity.
3. A die roll for a rotary die moulding machine used to mould bakery dough
for baked goods comprising:
a metal cylinder having a plurality of moulding cavities on a curved outer
surface thereof, with each moulding cavity having a first wall section
with a depth and shape corresponding to a thickness and shape,
respectively, of the baked goods to be moulded, and a second wall section
having an undercut edge beneath the first wall section, the first wall
section meeting the undercut edge at first and second peripheral areas of
the cavity, and an intermediate wall section extending from the first wall
section to the second wall section in the middle area of the cavity;
plastic inserts snugly within the moulding cavities, with each insert
comprising:
a face portion having a shape corresponding to the shape of the first wall
section of the moulding cavity;
a base portion having a shape corresponding to the shape of the undercut
edge of the second wall section of the moulding cavity;
a designed surface on the face portion of the insert concentrically curved
relative to the outer surface of the metal cylinder thereby forming a
space for moulding the bakery dough and having a design to be imprinted
into the baked goods; and
each insert being made from an integrally molded plastic material
sufficiently resilient to be snappably insertable into the moulding
cavities and to seal against the first and second wall sections thereof.
4. The die roll according to claim 3, wherein the base portion of the
insert includes a flat base surface which rests against a complimentary
flat bottom surface of the moulding cavity.
5. The die roll according to claim 3, further comprising a location tab on
the base portion of the insert which fits into a complimentary location
recess in the moulding cavity of the die roll.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a rotary die moulding machine, and in particular
to a plastic insert or wafer on a die roll of a rotary die moulding
machine used for making cookies, biscuits and other baked goods.
2. Background of the Related Technology
Commercial bakeries typically produce baked goods like cookies and biscuits
on a conveyor line or production line on which the goods are moulded and
baked on a conveyor system. One known and often used device for moulding
bakery dough is a rotary die moulding machine. The machine force feeds the
dough into an engraved cavity on a die roll to mould it with the desired
shape, thickness and design, and then removes the moulded dough blank from
the die roll and transfers it to a conveyor oven.
On the rotary die moulding machine, bakery dough is introduced between a
forcing roll and the die roll. The die roll, which is the heart of the
rotary die moulding machine, is a long metal cylinder which extends across
the width of the conveyor. The die roll, normally made from bronze, may be
one piece or made in sections and it has engraved into its outer surface a
number of cavities in the shape and design of the baked good to be
moulded. The dough is forced into the engraved cavities on the die roll
thereby moulding the dough into the desired shape and thickness and
imprinting it with a design. Excess dough is trimmed with a shear knife.
The moulded dough blank is then extracted from the cavity by pressing it
against a fabric extraction web which releases it from the die and then
transfers it to an intermediate web for deposit onto a baking band and
into an oven for baking.
Sandwich cookies such as OREOS.RTM. are commonly produced by this process.
Rotary die moulding machines are used to make a wide variety of shapes,
designs and thicknesses of baked goods.
Despite being widely accepted by high production commercial bakeries,
rotary die moulding machines have a number of disadvantages and
objectionable features. The engraved design in the cavity may become
roughened or slightly pitted due to the action of soda or ammonia and
other ingredients in the dough or by foreign objects inadvertently
introduced into the machine. Furthermore, bakery dough has a tendency to
stick to particularly intricate designs engraved into the cavity. For
these reasons the dough blank occasionally does not release well from the
cavity in the die roll, causing an accumulation of dough and greatly
reducing the definition of the detailed engraving imprinted on the baked
product. This results in difficulty in maintaining the specified weight of
the baked product as well as objectionable visual blemishes on the
surface.
TEFLON.RTM. or other nonstick surface treatments have been applied to die
rolls in an effort to improve release characteristics. Nonstick coatings,
however, wear off, especially when rougher types of bakery dough are used.
Reapplication of a nonstick coating is possible, but reapplication
requires removal of all the old coating. Removal and reapplication of
coatings requires that the die roll, shaft, and hubs be completely
disassembled, thoroughly cleaned by blasting with glass beads, cavities
de-burred, coated, heat treated, excess coating on the outer surface of
the die roll removed and re-assembled. This process typically takes the
die roll out of service two to three weeks, and costs 12 to 15 percent of
the cost of a new die.
An engraved die roll is also expensive to make, and, if only one of the
engraved cavities becomes disfigured, replacement of the entire die roll
may be required. In an effort to reduce cost, one known system provides a
replaceable metal insert for the die cavities, depicted in FIG. 8 of the
drawings. On this known system, the die roll cavity is formed as a simple
bore with straight sides. The metal insert is placed into the cavity and,
from within the center of the die roll, bolted into the bore. In the event
a foreign object disfigures the designed face on a particular metal
insert, the metal insert may be replaced. However, replacement of the
metal insert requires an extensive amount of labor to access the center of
the roll to unbolt the insert and install a new one. After replacing the
insert(s), the die surface must then be machined on a lathe to ensure that
the new inserts are at the same surface level as the others, which may be
different because of wear. Further, bakery dough and shortening have a
tendency to be forced into the crevice between the bore wall of the cavity
and the side of the insert, which is extremely difficult to remove and
causes a sanitary problem.
SUMMARY OF THE INVENTION
A plastic rotary die moulding insert system for moulding bakery dough to
make cookies, biscuits and other baked goods is disclosed. The system
includes a bore or moulding cavity in a rotary die roll with an undercut
edge, and a plastic wafer or insert snugly snapped into place in the
cavity. The plastic insert has a design on its face for imprinting the
design on the bakery dough.
The plastic insert provides a die roll with excellent release
characteristics for bakery dough. In the event the design on the face of
the plastic insert becomes disfigured or worn, the plastic insert can be
easily removed and replaced without having to disassemble the die. The
undercut edge of the moulding cavity firmly locks the plastic insert in
place. Because of the undercut edge, dough does not collect in the crevice
between the side of the insert and the wall of the moulding cavity.
Plastic inserts may be installed on the die roll under normal room
temperatures, so the die roll is not subject to the cost or lost time
involved with applied coatings. The plastic inserts also tolerate the
temperatures encountered in cleaning operations for sanitation purposes.
The plastic insert can be either of constant thickness, with the moulding
cavity milled out parallel to the outer surface of the die roll and the
undercut following the same contour, or the bottom of the cavity can be
flat, with the plastic insert having a variable thickness to make up the
difference. The effect is the same; the machining cost or the size of the
cavity will dictate which method to use in each instance.
The primary objects of the invention are therefore to provide a rotary die
moulding insert system which includes a plastic insert in the moulding
cavity of the die roll; to provide a plastic insert for the moulding
cavity of the die roll which has improved release characteristics for
bakery dough over an engraved metal cavity; to provide a plastic insert
which is easily replaceable when worn or damaged; to provide a plastic
insert which easily and snugly snaps into the moulding cavity of a die
roll; to provide the moulding cavity of the die roll with an undercut edge
to prevent dough from collecting in the crevice between the insert and the
cavity wall; to provide a plastic insert for a die roll which tolerates
normal operating temperatures and cleaning temperatures; to provide a
rotary die moulding insert system which is adaptable for making baked
goods having a wide range of shapes, designs and thicknesses.
Other objects and advantages of the invention will become apparent from the
following description which, in connection with the accompanying drawings,
sets forth by way of illustration and example certain embodiments of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings, which constitute a part of this specification and include
exemplary embodiments of the invention, include the following:
FIG. 1 is an isometric drawing of the essential features of a rotary die
moulding machine;
FIG. 2 is an isometric drawing of a die roll for a rotary die moulding
machine;
FIG. 3 is a cross-section view of the die roll taken at line 3--3 of FIG. 2
and a side view of a plastic insert prior to insertion into moulding
cavity in the die roll;
FIG. 4 is also a cross-section view of the die roll with the plastic insert
in place within the moulding cavity;
FIG. 5 is a cross-section view of the die roll and plastic insert taken at
line 5--5 of FIG. 4;
FIG. 6 is a perspective view of the plastic insert for the die roll;
FIG. 7 is comparable to FIG. 3 but shows a second embodiment of the
invention wherein the moulding cavity is formed with a curved bottom
surface and showing a curved, constant thickness plastic insert; and
FIG. 8 is a view of the prior art insert system discussed above.
DETAILED DESCRIPTION
On a rotary die moulding machine used in the commercial production of
cookies, biscuits and other baked goods, bakery dough is introduced
between a forcing roll FR and die roll 10. The dough is forced into
moulding cavities 12 on the die roll 10 at which point the dough is
moulded into the desired shape and thickness and imprinted with a design.
Excess dough is trimmed by shear knife K. The dough blanks are extracted
from the moulding cavities 12 by extraction web EW and transferred to
intermediate web IW for baking.
The die roll 10 is a long cylindrical shell extending across the width of
the extraction web EW. The die roll 10 may be made of aluminum or bronze,
and the die roll may be made in one piece as shown in FIG. 2, or made in
sections. The moulding cavities 12 are bored or milled at numerous
locations into the outer surface 11 of the cylindrical die roll 10.
Each moulding cavity 12 on the die roll 10 is machined to snugly hold a
complementary plastic insert 20. In general, each moulding cavity 12 is
machined with a bottom surface 13, a first wall section 14, and a second
wall section 15 with an undercut edge 16. The first wall section 14 is
machined at an angle, usually about fifteen degrees (15.degree.), from the
perpendicular to the outer surface 11 of the die roll 10. This angle,
which is maintained at each point around the perimeter of the moulding
cavity 12, allows the dough blanks to be easily extracted from the
moulding cavity without distortion. The second wall section 15 is machined
with an undercut edge 16 beneath the first wall section 14. Further, the
bottom edge of the second wall section 15 is machined down to the same
level as the bottom surface 13. The complimentary plastic insert 20 has a
shape and dimensions corresponding to those of the first and second wall
sections, 14 and 15, respectively. When the plastic insert 20 is inserted
into the moulding cavity 12, the plastic wafer 20 fits and seals in the
space formed by the second wall section 15 and the undercut edge 16.
FIGS. 3-6 show a first embodiment of the insert system wherein the bottom
surface 13 of the molding cavity 1 is machined flat and the plastic insert
20 varies in thickness. A second embodiment is shown in FIG. 7 in which
the bottom surface 13' is machined to a constant depth relative to the
outer surface of the die roll 10' and the plastic insert 20' has a
constant thickness. The specific details of the first and second
embodiments are described below.
In the first embodiment shown in FIGS. 3-6, each moulding cavity 12 is
machined to form a flat bottom surface 13, a first wall section 14 and a
second wall section 15. The first wall section 14 of the moulding cavity
12 extends from the outer surface 11 of the die roll 10 inwardly to a
depth corresponding to the desired thickness of the baked good being
moulded. The first wall section 14 is also machined to a shape
corresponding to the desired shape (e.g. circle, rectangle, etc.) of the
baked good being moulded. The second wall section 15 extends further
inwardly to the flat bottom surface 13. Further, the second wall section
15 has an undercut edge 16 beneath the first wall section 14. In other
words, the moulding cavity 12 is machined so that the first wall section
14 overhangs the second wall section 15, as shown in FIGS. 3, 4 and 5.
Looking at FIGS. 3 and 4, the bottom surface 13 of the moulding cavity 12
is flat while the outer surface 11 of the cylindrical die roll 10 is
arcuate or curved. The distance between the flat bottom surface 13 and the
curved outer surface 11 therefore changes depending on where the distance
is measured. In other words, the distance between the curved outer surface
11 of the die roll 10 and peripheral areas 13a and 13c of the flat bottom
surface 13 is less than the distance between the curved outer surface 11
of the die roll and the middle area 13b of the flat bottom surface 13.
This results in having the first wall section 14 meet the undercut edge 16
of the second wall section 15 above peripheral areas 13a and 13c of the
flat bottom surface 13. At middle area 13b of the cavity 12, where the
first wall section 14 and second wall section 15 do not meet due to the
curvature of the outer surface 11 of the die roll 10, an intermediate wall
section 17 extends from the first wall section 14 inwardly to the undercut
edge 16 of the second wall section 15.
Since the inner edge 17a of the intermediate wall section 17 is formed by
the undercut edge 16 of the second wall section 15, the inner edge 17a of
the intermediate wall section 17 is parallel to the flat bottom surface 13
of the moulding cavity 12. Since the outer edge 17b of the intermediate
wall section 17 is formed by the lower edge of the first wall section, the
outer edge 17b of the intermediate wall section 17 is therefore
concentrically curved relative to the outer surface 11 of the die roll 10.
The system further includes a plastic insert or wafer 20 which fits snugly
within the moulding cavity 12. The plastic insert 20, shown in FIG. 6, has
an outer face portion 21 and an inner base portion 22. The outer face
portion 21 is formed with a perimeter edge 23 in a shape (e.g. circle,
rectangle, etc.) which corresponds to the shape of the baked goods to be
moulded, which in turn corresponds to the shape of the first wall section
14 of the moulding cavity 12. The outer face portion 21 of the plastic
insert 20 further has a designed surface 24 for imprinting a design into
the bakery dough. The designed surface 24 is also concentrically curved
relative to the outer surface 11 of the die roll 10 and t the inner edge
of the first wall section 15 of the moulding cavity 12. When the plastic
insert 20 is placed within the moulding cavity 12, the design surface 24
is therefore displaced a constant distance from the outer surface 11 of
the cylindrical die roll 10. As forcing roll FR presses the bakery dough
into the moulding cavity 12 on the rotating die roll 10, the dough blank
is thus moulded to a uniform thickness.
The inner base portion 22 of the plastic insert 20 comprises a disk-like
section having a flat base surface 25 and an edge 26 protruding slightly
outward relative to the perimeter edge 23 of the outer face portion 21.
When the plastic insert 20 is inserted into the moulding cavity 12, the
flat base surface 25 rests against the complementary flat bottom surface
13 of the moulding cavity 12. The shape of the protruding edge 26 of the
base portion 22 on the plastic insert 20 corresponds to the shape of the
undercut edge 16 of the second wall section 15 of the moulding cavity 12
which snugly holds the plastic insert 20 in place.
The plastic insert 20 is preferably made from a sufficiently resilient
material and dimensioned so that it may be forced and snapped into the
moulding cavity 12. The plastic insert 20 must fit within the moulding
cavity 12 snugly or tightly enough to inhibit dough from forcing itself
into the crevice between the edge of the plastic insert 20 and the wall of
the moulding cavity 12. The plastic insert 20 may be made from a nylon and
TEFLON.RTM. based material called DELRIN.RTM. by DuPont or from any other
FDA approved material which provides sufficient resiliency t allow the
insert 20 to be snapped into and held tightly in the moulding cavity 12 on
the die roll 10 and provides the desired release characteristics for dough
blanks.
The production of round cookies requires both the moulding cavity 12 and
the plastic insert 20 to be round, as shown in the drawings. To ensure
proper orientation of the plastic insert in the moulding cavity 12, the
base portion 22 of the plastic insert 20 may be provided with a location
tab 27, or a pair of tabs as shown, which fits into a complimentary
location recess 28 in the moulding cavity 12.
In the second embodiment shown in FIG. 7, the bottom surface 13', the
second wall section 15' and the undercut edge 16' are concentrically
curved relative to the outer surface 11' of the die roll 10'. The plastic
insert 20', in this case, has a constant thickness. The plastic insert 20'
may be formed with a curve to fit into the curved moulding cavity 12', or
in some applications the plastic insert 20' may be originally formed flat
and then as the insert is forced into the curved moulding cavity 12' the
resilient plastic material allows it to conform to the curved surfaces of
the cavity 12'.
Although the drawings show an insert system for a round sandwich cookie,
the system may be modified using the principles disclosed above to produce
cookies shaped like rectangles, stars, ovals, peanuts, animals, windmills,
and nearly every other shape of commercially produced baked goods
currently on the market. The system may also be modified to produce baked
goods having a wide range of thicknesses and imprinted with designs to
depict letters, numbers, ridges, swirls, insignias, and so on.
Therefore, specific structural and functional details disclosed herein are
not to be interpreted as limiting, but merely as a basis for the claims
and for teaching on skilled in the art to variously employ the present
invention in any appropriately detailed structure. Changes may be made in
the details of construction, arrangement and operation of the invention
without departing from the spirit of the invention, especially as defined
in the following claims.
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